The present invention generally relates to a protective cover for objects. More particularly, the invention relates to a seat cover for the protection of a motor vehicle seat, especially for initially equipping. The invention also relates to a method of manufacturing such seat covers of plastic foil.
Seat covers made of plastic foil are put on, or drawn over automobile seats in order to avoid soiling the automobile seat by workers and other persons. The use of such seat covers has been known in car repair shops when an inspection or a repair is carried out at the automobiles. Also when initially equipping an automobile, i.e. in the automobile manufacturing plant, when the automobile is assembled, the automobile seats are already exposed to a possibility of being dirtied. This risk of being dirtied starts already in the automobile seat manufacturing plant and when supplying the seats to the automobile manufacturing plant. It continues when the seats are placed on the conveyors which, in the end, lead to the assembly line of the automobile. Also during the assembly of the automobile, a plurality of mechanics successively comes in contact with the automobile seats. Finally, the assembled automobile must be driven off the belt, driven onto trucks or freight cars and finally handled again several times at the car dealer, until finally the automobile is turned over into the hands of the buyer or purchaser, respectively. From the fabrication of the seat at the supplier until the delivery of the automobile to the purchaser or customer, the automobile seats come into contact with approximately 30 to 35 mechanics and other persons, so that there is a considerable dirt risk. In order to counteract this dirt risk, seat covers made of plastic foil have been known which are pulled over the automobile seats, especially over the driver""s seat, often already at the seat manufacturer, but at the latest at the automobile manufacture, and are removed just before the automobile is delivered to the customer. Such temporary seat covers do not normally differ from the seat covers which are used during the inspection or repair of an automobile. They can be made of a comparatively thick plastic foil which withstands greater wear.
A seat cover is known from German patent DE 41 32 714 C1. The regions of the rear layer forming the two pockets are connected by connection strips which extend across the free edges of the regions forming the pockets along the transverse welding. The connecting strips are also connected with the front layer so that the substantially continuous rear layer includes a recess with closed edges. The two layers of the seat cover, i.e. the front layer and the rear layer, thus includes a contour of the same size and are joined with each other at all four edges, continuously in the region of the transverse welding as well as in the region of the longitudinal edges. While the front layer is designed as a continuously closed piece, there is a recess in the rear layer which is arranged at all sides and at a distance from the contour of the seat cover lying flat and represents the only recess by means of which the seat cover can be pulled over the backrest and the seat cushion. By means of the connecting strips, apart from the two previously known pockets, additional transverse pockets connecting the pockets are created which reach behind the backrest in the transition region and, thus, effectively protect the automobile seat in these exposed places against dirt. The risk of the seat cover slipping off when using the automobile seat which is protected by the seat cover has practically been eliminated. In spite of that, handwork is avoided totally during the manufacture of this seat cover. The additional use of rubber bands, foil strips and the like is no longer required either, and there is no additional assembly work any more. Rather, when pulling on the seat cover, it automatically arrives in its protecting position enveloping the seat cushion as well as the backrest. By means of transverse welding the front layer is continuously joined with the rear layer at each seat. On the other hand, the transverse welding can be done in a way that the individual seat covers are separated from each other at the same time, so that they can be put down stacked one upon the other and in this manner can be shipped to the seat manufacturer or the automobile manufacturer. Besides, it is also possible to leave the individual seat covers joined by perforations and to wind such an endless line on a storage spool. The plastic foil used to manufacture the seat covers has only minor thickness for reasons of economizing on material, so that when pulling it on, there is a risk of tearing. In such a case the proper fit of the seat cover on the automobile seat is no longer guaranteed.
When automobile seats suspended from a conveyor belt with their backrests pointing downward are supplied to the assembly line of the automobile, there is further the risk that the seat covers inadvertently slip from the automobile seat and drop. Thus, they no longer fulfill their protective function. In order to counteract this risk, it has been known to use a rubber band as separate part of the seat cover which, after pulling the seat cover over the backrest, is guided over the backrest as closed loop in a way that it fits between the seat cushion and the backrest in the transition region. Through this step the unintentional dropping of a seat cover from a suspendedly conveyed automobile seat is prevented. At the same time, the front layer of the seat cover is fixed by the rubber band in the transition region between seat cushion and backrest, so that the risk of slipping out of place is counteracted. However, the use of such rubber bands in addition to seat covers is more costly and is only a limited cure against the risk of dirt.
Instead of the additional use of a rubber band, it has also been known to weld two foil strips to approximately the middle region of the free edge of the pocket which envelopes the backrest. These two foil strips are looped forward across the seat, in the way of strings of an apron, and are knotted together there, so that also here a tighter fit of the front layer of the seat cover in the transition region between seat cushion and backrest is achieved. The manufacture of this additional foil strip and especially the welding is costly, after placing the seat cover it requires an additional knotting step and, furthermore, also is only a limited remedy against the risk of dirt. Compared with a rubber band, the foil strips are placed comparatively too high at the backrest.
It is also known in the art to manufacture a seat cover as described in German DE-AS 16 30 878. The known seat cover has been further developed, as it is generally known in the art. After separating the line of plastic into the individual seat covers, a half-tube is welded along the free edges of the pockets formed by the rear layer as well as along the free edges of the front layer in the region not covered by the pockets. When welding the half-tube, a rubber band in the form of a loop is inserted. With this rubber band an opening is created at the seat cover, which is used to pull it over the automobile seat, the rubber band exerting a certain stretching effect so that especially the front layer of the seat cover is held closer to the seat cushion and to the backrest. Such a seat cover is especially time-consuming and expensive because of the welding of the half-tube with the rubber band, which is done by hand, but on the other hand it achieves effective protection. Putting such a seat cover over an automobile seat is comparatively more difficult than is the case with the seat cover described initially.
Further, it has been known to shrink the seat cushion on the one hand and the backrest on the other hand into one each shrink foil piece already at the manufacturer""s of the automobile seat, and only subsequently when mounting the seat, to bring the seat cushion and the backrest together. These two parts of shrink foil then remain on the automobile seat and protect it on its entire way from automobile manufacturer to the delivery of the automobile to the customer or purchaser. The shrinking, however, signifies considerable additional expenditure, also for the respective shrink devices.
Further, it has been known, particularly from low-wage countries, to sew a rubber band onto the edge of a plastic foil seat cover opening with closed edges. The sewing is done by hand and by fixing the rubber band under bias. As a consequence, the rubber band as an elastic foreign element contracts and the non-elastic foil forms wrinkles. This does not only disturb the appearance, but also prevents winding onto a spool. Even as individual pieces in a stack such seat covers are hard to handle. More disadvantages, such as wrinkled fit on the automobile seat, a sensitivity to electronic barriers or the like, initial tearing and continued tearing of the foil are a consequence.
Briefly described, the present invention provides a protective cover for objects. The cover includes a continuous protecting front layer and a rear layer being connected to the front layer by welding. The rear layer includes a recess with closed edges. At least a portion of the rear layer is made of an elastic and retractable material. A pocket is formed by the rear layer and the front layer. For example, the invention also relates to a steering wheel protection with a circular front layer which is joined wrinkle-free with a rear layer, to a tire protection, for example the spare tire or a snow tire. The protective cover can also be used for the protection of pillows, armchairs or other furniture or for parts of furniture. It can also be used for the protection of shopping trolleys in supermarkets. Another application relates to the field of hygiene and hospitals. In these cases the protective cover can be pulled on a mattress or a part of a mattress. In all of these cases, the front layer can be used as advertising carrer.
The present invention also provides a seat cover to be mounted on a motor vehicle seat to protect the seat. The seat cover includes a continuous front layer of plastic foil being designed and arranged to protect the surface of a seating and of a backrest of a motor vehicle seat. A rear layer of plastic foil is connected to the front layer by transverse welding, and tt includes a recess with closed edges. At least a portion of the rear layer is made of an elastic and retractable material. A first pocket is formed by the rear layer and the front layer, and it is designed and arranged to receive at least a portion of the backrest of the seat. A second pocket is formed by the rear layer and the front layer, and it is designed and arranged to receive at least a portion of the seating of the seat.
The present invention also relates to a method of producing seat covers for the protection of motor vehicle seats. The method includes the steps of forming a first line of a flat plastic foil defining a front layer of the seat cover, forming a second line of a flat plastic foil defining a rear layer of the seat cover, at least a portion of the rear layer being made of an elastic and retractable material, punching a recess into the second line defining the rear layer of each cover, and connecting the first and second line by at least one transverse welding and by at least one longitudinal welding.
The invention starts from the idea to modify the material properties of the plastic foil used for the manufacture of the seat cover in a way that the seat cover can be removed at least partly from the seat cushion of the automobile seat and put on again. This is intended to be possible at least several times without the plastic foil tearing or the tight fit substantially relaxing or losing effect after putting the cover on again. Thus, the issue is the use of an elastic foil for at least certain regions of the seat cover. The elasticity and the retractability connected therewith are employed in order to allow removal and re-placement. This can be meaningful already when mounting the automobile seat in the automobile, because in removed condition fixing screws of the seat are easier to reach. Also when mounting a drawer, a fire extinguisher, a first aid kit or the like it can be useful or even required to temporarily loosen the seat cover pocket which envelopes the seat cushion without loosening the seat cover pocket enveloping the backrest. A similar thing applies to the connection or the setting of seat motors which adjust the seat position, ventilation devices and the like. In such cases it can happen that the seat cover must be removed about ten times or more and pulled on again. Also after that the seat cover must fulfill its protective function properly. The seat cover can advantageously be manufactured in smaller dimensions than before. In spite of that, the elasticity of a stretchable foil renders an easy handling when pulling the seat cover on and it provides a better fit. The seat cover obtains gum-elastic properties, so to say, and the retractability is exploited advantageously. In put-on condition the seat cover adapts exactly to the contours of the automobile seat. Thus, there is no possibility of interference if, for example, the correct position of the automobile seat in the automobile is measured and checked by means of electronic barriers. Projecting foil pieces or wrinkles of the seat cover on the automobile seat can no longer lead to a disturbance. The new seat cover also has advantages when putting it or pulling it onto an automobile seat. It can be pulled on quickly and securely as well as wrinkle-free tightly fitting the contours of the automobile seat.
The elastic foil is preferably used in the region of the rear layer of the seat cover and even there only in part or in regions, respectively. At least the connecting strips consist of the elastic retractable material. This already suffices in order to achieve the desired effect in the region of the pocket enveloping the seat cushion. But it is also possible to form larger regions of the rear layer or of the entire rear layer of the gum-elastic material.
The elastic retractable material preferably has such elasticity and such retractability that the seat cover can be pulled onto the automobile seat and pulled off again several times. This corresponds to the conditions of application in the mounting of an automobile seat at the assembly line of the automobile. In this process the foil must withstand such handling without tearing initially or continuing to tear. Particularly, the plastic foil forming the rear layer has an elastic stretch of at least 50%, preferably at least 60%. Whether a foil material meets these requirements can be determined in a simple test, for example as follows: Starting from a test strip of 50 mm length in unstretched condition, there is a briefly acting stretch of this test strip to 150 mm (200%) with subsequent relaxation. The test strip quickly assumes the remaining length of 75 mm, i.e. it plastically stretched from 50 mm to 75 mm. The total stretch of 200% consists of 50% plastic stretch and 150% elastic stretch. Thus, the tested plastic foil has an elastic stretch of 150%.
The opening with closed edges advantageously has an oval form or a rectangular form with rounded corners. This is advantageous from a number of aspects. The risk of tearing is further reduced and the tight fit is favored. The automobile seat is enclosed optimally and, thus, protected.
The rear layer can consist of a co-polymer, especially of ethylene vinylacetate or butene vinylacetate. Also other materials may meet the requirements, such as a thermoplastic elastomer or an especially elastic low-density material which is used at least in layers or in mixtures or 100%.
The rear layer can consist of a multilayer foil, one of the layers of which has high initial tearing and continued tearing resistance and the other layer has high retractability. The arrangement of the two layers relative to the automobile seat is optional.
The multilayer foil forming the rear layer may include a third layer with good welding properties, which layer is applied facing the front layer.
The plastic foil forming the front layer can be designed to be slip-proof on the inner surface facing the automobile seat and smooth on the outer surface. Thus, there is no risk that the seat cover slips out of place relative to the automobile seat when the automobile is assembled, even when the mechanics sit onto the automobile seat up to approximately 35 times, as is known.
The method of producing seat covers for the protection of motor vehicle seats starts from the point that lines are formed of plastic foil in the shape of flat foils which form the front layer and the rear layer and that the two lines are joined with each other for each cover by transverse welding and by at least one longitudinal welding. According to the invention, a recess with closed edges having oval or rectangular shape with rounded corners is placed into the line forming the rear layer of each seat cover in the way of a cut or a cutout. At least the rear layer is completely or partly formed of elastic, retractable material. Through the use of flat foils it is readily possible to combine and weld together different materials. The front layer and the rear layer can each be formed of a flat foil. The two lines are joined with each other via two longitudinal weldings. It is clear that these two longitudinal seams which are generated by the longitudinal welding extend in the conveying direction of the endless lines of the flat foils. Through this special shaping the two free corners of the seat cushion are enveloped especially effectively and extensively and protected. At the same time, the seat cover has the required mobility to be pulled over the automobile seat easily. Through this special design of the connecting strips the recess with closed edges is given an oval or rectangular shape. The recess with closed edges can be obtained by making a cutout, i.e. by a piece being cut out from the line of the rear layer. But it is also possible to obtain the recess only by a U-shaped cut and leaving a respective flap at the rear layer which has no disturbing effect when handling the seat cover. The recess with closed edges has rounded corners so that tearing of the plastic foil is avoided when pulling the seat cover over the automobile seat.
In the described manufacturing possibilities, the line forming the front layer and/or the line forming the rear layer can be designed to be slip-proof. This applies particularly to the line forming the front layer so that the seat cover cannot slip out of place laterally in this region, when it is exposed to stress by the mechanic or by other operating staff sitting on it and rising. The adherence of the front layer to the automobile seat relieves the stress on the weldings.